In general, in the turret type yarn winder, when an exchange of a full bobbin with a fresh empty bobbin is made, a yarn now being taken up is removed from a traverse guide to be transferred out of the normal traverse range of the yarn traverse mechanism with the aid of an exclusive guide means, is wound on an empty bobbin while the yarn is held by a yarn holding means secured, for example, on a base portion of a bobbin chuck, and then is severed from the full bobbin.
Due to the structure of a turret type winder, in which a pair of bobbin chucks are driven by a single motor, both chucks are driven at the same rotational speed, and the motor speed is controlled so that the chuck rotational speed becomes slower in accordance with an increase of a diameter of a bobbin held on the chuck now performing a winding operation and a yarn continuously delivered at a constant speed can be taken up without excessive tension or slack. During the above-described bobbin exchange operation, the yarn taken up on a full bobbin of a larger diameter is transferred to an empty bobbin of a smaller diameter driven at the same rotational speed as that of the former, which means that the yarn take-up speed is sharply lowered. Therefore, in a transition period until a desired rotational speed of a motor has been attained, which speed is controlled to correspond to a smaller diameter of a bobbin on which a yarn is freshly wound, the yarn is liable to be slackened due to the lower rotational speed of a bobbin chuck holding the empty bobbin, whereby a smooth yarn transfer and winding operation are hindered. To avoid this drawback, according to the conventional turret type winder, a plurality of dancer rolls are provided on a yarn feeding path to absorb yarn slack caused by the disparity between a yarn feeding speed and a yarn winding speed on a bobbin (see Japanese Examined Patent Publication No. 48-31178).
As stated above, a winder using an exclusive guide for a yarn transfer, provided other than a yarn traverse guide, has drawbacks in that it must have a complicated mechanism for driving the exclusive guide, the motion of which becomes inaccurate because of a repeated yarn transfer and often breaks down, which increases the man/hour required for the maintenance thereof.
On the other hand, the mechanism for absorbing a yarn slack by a series of dancer rolls at the beginning of a yarn transfer causes the total size thereof to be enlarged, and it is difficult to obtain the predetermined removal of yarn slack due to the rotational resistance of the dancer roll itself, as well as the yarn friction.